Yes it unscrews. You most likely will use this to drain your hull after loading the boat on the trailer. If you have another drain plug at the transom you can drain from that as well, but I always use just the center T-drain plug.

It looks like there is a drain plug on the side of the transmission, can I drain it there? I realize I just have to be careful and not spill the ATF all over the place. The transfer pump I picked up looks like it has different sized rubber plugs I can stick in the drain hole after I pull the plug so hopefully I can catch most of it that way.

I plan on using 15W-40 motor oil, should I change it to motor oil, run it a little then change it again or won't it matter if it's mixed?

I'm pretty sure that it's a 630V (been a long time since I looked at mine), but if you fold down that little flap of metal after the "HSW" in the model name, it'll be clear.

The Hurth Trans Noise service advisory I linked above suggests simply sucking out what you can, and calling it good when you convert "It is not necessary to flush the transmission, just get as much of the old fluid out as possible."

Delvac and Rotella are both fine oils; I'd buy whichever one is on sale. Both have the automobile rating called for by Indmar, so they're acceptable for use in the engine/trans. In general, the diesel oils are seen as being of higher quality than auto oils. For example, they had higher levels of zinc anti-wear additive for a lot of years, because in a car the zinc additive tends to degrade the catalytic converter over time which isn't a concern in a diesel. I believe both Rotella and Delvac reduced zinc levels a few years ago, so that may not be an advantage any more. They're also used in the heavy use, high power environment of over-the-road truckers where things like engine wear are tracked, so there's more incentive to keep quality high than in the auto market, where sales are driven by how much is spent on TV commercials rather than maintenance records. It's not clear if this is really true, but it makes me feel better so I use the diesel oils.

I actually made some progress today. I've been working on cleaning the interior, it's coming out okay. I have what I think is mold spots that will not come out. I've tried Totally Awesome, 303 and bleach on the back seat that I removed but I've had very little luck removing the spots.

Does anyone have any recommendations?

I started wet sanding then buffing the back of the boat, that is coming out very good. It's taking a lot of time but it's getting better. I'm sanding with 600, 1000, 1500 grit then buffing with 3M compounds.

I used my power washer to remove the rear Mastercraft sticker then took WD-40 to get the remaining adhesive off, that worked well.

Here is a picture of above the rub rail sanded.

I hope it's worth it, I drilled out the rivets that hold the cover snaps on so I did have to sand and buff around them.

Buffed and waxed!!!

Here I have the bottom sanded, it's ready to be buffed.

I used blue painters tape to protect the rub rail while buffing, it took a lot to get down in those corners by the rail.

I also pulled the dash out so I can figure out how I'm going to wrap it. I'm think about going with this.

Well I made some progress during the week and yesterday. I was able to remove the stickers, buff and wax the port side.

I also finished the lower rear section of the boat.

Today I removed the starboard stickers and buffed above the rub rail.

When I removed the port side rear "Mastercraft" sticker I used a heat gun and my fingers to scrape and peel the sticker, that worked okay but when I tried the Maristar one I was not having much luck. I tried a plastic wedge tool I have but as soon as it got warm it bent. I had an idea to sharpen a paint stir stick and that worked very well!!

At first I was using WD-40 to remove the remaining adhesive but then I tired some automotive solvent based wax and grease remover and that worked better.

He's the finished product ready to wet sand and buff.

I can't believe how long it has been taking!!! I've probably spent 4 hours today removing the stickers from one side and buffing above the rub rail.

I have the boat sitting in my driveway like that so I can work between the garage and the boat out of the sun in the evenings, the sun rises behind my house and sets in front of it.

I'm hoping the machine shop will have all the machine work done to the block and heads this week so I can get the bearings and gaskets ordered I will need. I'm planning on having them assemble the short block.